'\" te
.\" Copyright (c) 2005, Sun Microsystems, Inc.
.\" All Rights Reserved.
.\" The contents of this file are subject to the terms of the Common Development and Distribution License (the "License").  You may not use this file except in compliance with the License.
.\" You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE or http://www.opensolaris.org/os/licensing.  See the License for the specific language governing permissions and limitations under the License.
.\" When distributing Covered Code, include this CDDL HEADER in each file and include the License file at usr/src/OPENSOLARIS.LICENSE.  If applicable, add the following below this CDDL HEADER, with the fields enclosed by brackets "[]" replaced with your own identifying information: Portions Copyright [yyyy] [name of copyright owner]
.TH CPC_COUNT_USR_EVENTS 3CPC "Mar 28, 2005"
.SH NAME
cpc_count_usr_events, cpc_count_sys_events \- enable and disable performance
counters
.SH SYNOPSIS
.LP
.nf
cc [ \fIflag\fR... ] \fIfile\fR... \(milcpc [ \fIlibrary\fR... ]
#include <libcpc.h>

\fBint\fR \fBcpc_count_usr_events\fR(\fBint\fR \fIenable\fR);
.fi

.LP
.nf
\fBint\fR \fBcpc_count_sys_events\fR(\fBint\fR \fIenable\fR);
.fi

.SH DESCRIPTION
.sp
.LP
In certain applications, it can be useful to explicitly enable and disable
performance counters at different times so that the performance of a critical
algorithm can be examined.  The \fBcpc_count_usr_events()\fR function can be
used to control whether events are counted on behalf of the application running
in user mode, while \fBcpc_count_sys_events()\fR can be used to control whether
events are counted on behalf of the application while it is running in the
kernel, without otherwise disturbing the binding of events to the invoking LWP.
If the \fIenable\fR argument is non-zero, counting of events is enabled,
otherwise they are disabled.
.SH RETURN VALUES
.sp
.LP
Upon successful completion, \fBcpc_count_usr_events()\fR and
\fBcpc_count_sys_events()\fR return \fB0\fR. Otherwise, the functions return
\fB\(mi1\fR and set \fBerrno\fR to indicate the error.
.SH ERRORS
.sp
.LP
The \fBcpc_count_usr_events()\fR and \fBcpc_count_sys_events()\fR functions
will fail if:
.sp
.ne 2
.na
\fB\fBEAGAIN\fR \fR
.ad
.RS 11n
The associated performance counter context has been invalidated by another
process.
.RE

.sp
.ne 2
.na
\fB\fBEINVAL\fR \fR
.ad
.RS 11n
No performance counter context has been created, or an attempt was made to
enable system events while delivering counter overflow signals.
.RE

.SH EXAMPLES
.LP
\fBExample 1 \fRUse \fBcpc_count_usr_events()\fR to minimize code needed by
application.
.sp
.LP
In this example, the routine \fBcpc_count_usr_events()\fR is used to minimize
the amount of code that needs to be added to the application. The
\fBcputrack\fR(1) command can be used in conjunction with these interfaces to
provide event programming, sampling, and reporting facilities.

.sp
.LP
If the application is instrumented in this way and then started by
\fBcputrack\fR with the \fBnouser\fR flag set in the event specification,
counting of user events will only be enabled around the critical code section
of interest.   If the program is run normally, no harm will ensue.

.sp
.in +2
.nf
int have_counters = 0;
int
main(int argc, char *argv[])
{
    if (cpc_version(CPC_VER_CURRENT) == CPC_VER_CURRENT &&
        cpc_getcpuver() != -1 && cpc_access() == 0)
        have_counters = 1;

    /* ... other application code */

    if (have_counters)
        (void) cpc_count_usr_events(1);

    /* ==> Code to be measured goes here <== */

    if (have_counters)
        (void) cpc_count_usr_events(0);

    /* ... other application code */
}
.fi
.in -2

.SH ATTRIBUTES
.sp
.LP
See \fBattributes\fR(7) for descriptions of the following attributes:
.sp

.sp
.TS
box;
c | c
l | l .
ATTRIBUTE TYPE	ATTRIBUTE VALUE
_
MT-Level	MT-Safe
_
Interface Stability	Obsolete
.TE

.SH SEE ALSO
.sp
.LP
.BR cputrack (1),
.BR cpc (3CPC),
.BR cpc_access (3CPC),
.BR cpc_bind_event (3CPC),
.BR cpc_enable (3CPC),
.BR cpc_getcpuver (3CPC),
.BR cpc_pctx_bind_event (3CPC),
.BR cpc_version (3CPC),
.BR libcpc (3LIB),
.BR attributes (7)
.SH NOTES
.sp
.LP
The \fBcpc_count_usr_events()\fR and \fBcpc_count_sys_events()\fR functions
exist for binary compatibility only. Source containing these functions will not
compile. These functions are obsolete and might be removed in a future release.
Applications should use \fBcpc_enable\fR(3CPC) instead.
